Calpain Project, The Tokyo Metropolitan Institute of Medical Science (Rinshoken), Japan.
Exp Anim. 2010;59(5):549-66. doi: 10.1538/expanim.59.549.
Calpains are intracellular Ca²(+)-dependent cysteine proteases (Clan CA, family C02, EC 3.4.22.17) found in almost all eukaryotes and some bacteria. Calpains display limited proteolytic activity at neutral pH, proteolysing substrates to transform and modulate their structures and activities, and are therefore called "modulator proteases". The human genome has 15 genes that encode a calpain-like protease domain, generating diverse calpain homologues that possess combinations of several functional domains such as Ca²(+)-binding domains and Zn-finger domains. The importance of the physiological roles of calpains is reflected in the fact that particular defects in calpain functionality cause a variety of deficiencies in many different organisms, including lethality, muscular dystrophies, lissencephaly, and tumorigenesis. In this review, the unique characteristics of this distinctive protease superfamily are introduced in terms of genetically modified animals, some of which are animal models of calpain deficiency diseases.
钙蛋白酶是一种存在于几乎所有真核生物和部分细菌中的细胞内 Ca²(+)-依赖性半胱氨酸蛋白酶（Clan CA，家族 C02，EC 3.4.22.17）。钙蛋白酶在中性 pH 下具有有限的蛋白水解活性，可将底物进行蛋白水解，从而改变和调节其结构和活性，因此被称为“调节蛋白酶”。人类基因组中有 15 个基因编码钙蛋白酶样蛋白酶结构域，产生多种钙蛋白酶同源物，它们具有 Ca²(+)-结合结构域和锌指结构域等多种功能结构域的组合。钙蛋白酶在生理功能中的重要性体现在，其功能的特定缺陷会导致许多不同生物体的多种缺陷，包括致死、肌肉萎缩症、无脑回畸形和肿瘤发生。在本文中，将从基因修饰动物的角度介绍这种独特的蛋白酶超家族的特征，其中一些是钙蛋白酶缺乏疾病的动物模型。
